Toxicology Flashcards
What are antidotes to beta blocker and CCB toxicity?
Intralipid
Insulin and dextrose
Glucagon
Calcium (for CCBs)
Vasopressors
What is the typical illness script for a Copperhead bite?
Usually, it happens on a hand or foot. The initial symptoms are localized swelling and redness. The worst symptoms happen at 18-36 hours after the bite.
When should you treat a Copperhead bite with CroFab?
If someone has skin/MSK findings that progress past a joint line or they are having concerning progression of symptoms.
When should you use a tourniquet or suction on a snakebite?
Never. Tourniquets can cause concentrated tissue necrosis. Suction (with or without cutting) can cause localized inflammation that can deepen the path of venom into the wound.
True or false: baby snake bites are worse than adult bites.
False
When should you admit a person with a snake bite?
If you’ve given antivenom, recommend an observational admission.
How long after giving antivenom should you wait to reassess before redosing?
About 30 minutes It takes 30-60 minutes after finishing the bolus to reach peak effect.
When evaluating a snake bite, look for _____________.
oozing at fang marks – this is a reliable sign of envenomation
What are the two types of venomous snakes in the US?
Crotaline (copperheads, rattlesnakes) and Elapidae (coral snakes)
Crotaline toxin causes what lab abnormalities?
Thrombocytopenia and elevated INR
What immediate management should you do with snake bites?
- Immobilize the limb
- Remove jewelry on the affected limb
- Mark the leading edge of erythema
What physical exam things should you look for in a snake bite?
- Fang marks with oozing (sign of envenomation)
- Progression of erythema/edema
- Compartment syndrome
The mean age of people dying from opiates is ______.
37
Starting MAT in someone presenting from an overdose in the ED has been shown to decrease 1 year mortality by ___________.
59%
What are the side effects of methadone?
- Prolonged QT
- Tooth decay
True or false: methadone is a partial agonist.
False Buprenorphine is a partial opioid agonist. Methadone is a full agonist.
True or false: buprenorphine is a potent respiratory depressant.
False
Because it is a partial agonist, buprenorphine has a high ceiling of respiratory effects. It will typically only cause apnea if combined with something else.
You should only start buprenorphine when your patient is ___________.
in withdrawal
Because buprenorphine is a partial agonist, it can precipitate withdrawal if someone is still high.
Describe the screening process for lead toxicity in children.
Kids are screened with a capillary stick. If this is elevated (greater than 5 ug/dl) then you confirm with a venous lead. If the venous is 5-45 ug/dl you council on prevention strategies and rescreen later. If the venous is greater than 45 ug/dl you begin chelation therapy.
In general, when you see that someone is having unpleasant side effects from a drug but their levels are normal, try ______________.
decreasing the dose
Learning point: the drug level isn’t everything. You can have side effects at any dose.
____________ are the first-line treatment for PCP-associated agitation.
Benzodiazepines
Haldol as backup.
Saw palmetto is commonly used to treat as a supplement for what?
BPH
What are side effects of saw palmetto?
GI upset and increased bleeding risk
What are side effects of ginseng?
Increased bleeding risk
___________ (a supplement for post-menopausal hot flashes) can cause hepatotoxicity.
Black cohosh
Kava can cause ______________.
liver injury
What supplement (that is also a food) can cause hypokalemia?
Licorice
What is the big difference between CCB toxicity and beta blocker toxicity?
CCBs cause hyperglycemia whereas BBs cause hypoglycemia.
Review the protocol for treating radiation exposure.
The first and most important thing is to decontaminate the person exposed. Their clothing is likely radiating, so you need to remove all clothing and wash them down. Only when their Geiger readings are ≤ 2x the background radiation can they safely be around other people.
What factors portend a poor prognosis in acute radiation syndrome?
Early GI symptoms
48 hour ALC < 1.5
Those with a rising salicylate level on recheck may need what therapy?
Hemodialysis
If you need to make a bicarbonate solution, do not use what IV solution?
Normal saline
Bicarbonate solution has high amounts of sodium, and if you add it to a NS solution then you will make them hypernatremic.
The toxic level of acetaminophen is _______ mg/kg.
150
So for a 70 kg adult it is 10 g.
Review the management of puss moth caterpillar injuries.
Puss moth caterpillars are insects covered in a toupee-like fuzz. They are found in the eastern US. They can release venom from their stings that then causes local tissue injury.
Manage by using tape to remove any unseen spines stuck in the skin. Wash the area with soap and water. Numb with topical lidocaine. Support with NSAIDs and antihistamines.
What is a beta particle?
It is a high energy electron or positron that can cause damage.
Why is it a good idea to distance yourself from radiation sources?
The amount of exposure is inversely proportional to the square of the distance, so doubling your distance decreases the exposure by a factor of four.
Why is polonium used in poisonings (like the KGB did to Litvinenko in 2006)?
Polonium is the last radioactive element in the decay chain of uranium before lead. It only emits alpha particles, so if you put it in a vial it will be undetectable and not harmful to anyone. It is only harmful if ingested.
The three mantras of limiting radiation exposure for healthcare workers is what?
Time, distance, shielding
Limit your time around the person, increase the distance, and wear shielding
What is the priority of decontamination by body site?
1st: wounds
2nd: orifices
3rd: intact skin
Acute radiation syndrome can begin at what radiation exposure level?
0.2 Gy for hematopoietic effect, 1 Gy for clinical symptoms
The first lab abnormality to show up in acute radiation syndrome is what?
ALC drop (within 48 hours if clinically significant)
Vomiting within _______ after a radiation exposure is suggestive of lethal dose of radiation.
1 hour
If you are concerned about radiation sickness, a good resource is _______________.
Radiation Emergency Medical Management (REMN); they have an app
Explain dry decontamination.
Water can activate some substances, so if there is physically something visible on the patient you should attempt to brush it off dry before using water.
Tide pod ingestion should be treated with what?
Water
Laundry detergent is alkaline. Water helps dilute it.
Review the management options for beta-blocker overdose.
- For hypotension: IV fluids and vasopressors
- For refractory shock: high-dose insulin, calcium salts
- For hypoglycemia: glucagon
- For coma: lipid emulsion
What drug can mimic opioid overdose?
Clonidine
It causes apnea, hypotension, lethargy, and miosis.
The treatment for organophosphate poisoning is _____________.
atropine (titrated to secretions) and pralidoxime (2-PAM)
What is 2-PAM?
2-pyridine aldoxime methylchloride (aka, pralidoxime)
Sarin gas has what toxidrome?
Cholinergic
What order do you need to given atropine and pralidoxime?
Atropine then pralidoxime
Pralidoxime reactivates acetylcholinesterase, but it temporarily inhibits it first, thereby worsening cholinergic symptoms. Atropine should be given first to decrease this effect.
Review the cholinergic toxidrome.
Bradycardia
Bronchospasm
Sialorrhea
Lacrimation
Urinary incontinence
Delirium
GI distress
Eyes (miosis, just remember it’s the opposite of atropine)
Sweating
What is the dose of atropine for organophosphate toxicity?
2 mg
Double dose every 3 minutes until they no longer have wheezing or bronchorrhea.
Which toxidrome antidote has to be given quickly or else it won’t work?
Pralidoxime
If there is a significant delay after exposure to organophosphates then the toxin-acetylcholinesterase compound “ages” and gets less amenable to reversal.
What toxin can cause optic neuritis?
Methanol
What physical exam finding is seen in lead toxicity?
Burton’s line – a line of gray-blue discoloration of the gingiva next to the teeth
Which antiepileptic can cause AGMA in toxic levels?
Topiramate
What metabolite accounts for the AGMA seen in methanol ingestion?
Formic acid
Cholinergic toxicity is seen in what two scenarios?
- Organophosphates (farm workers)
- Dementia patients (who take rivastigmine or donepezil)
CPRHHH is what toxidrome?
Opioid
- Coma
- Pinpoint pupils
- Respiratory depression
- Hypotension
- Hypothermia
- Hyporeflexia
What antidote would you give someone who had a wide-complex tachycardia after huffing an inhalant?
Esmolol
The hydrocarbons in inhalants are thought to induce dysrhythmias by over-sensitization to catecholamines.
What is scombroidosis?
Histamine fish toxicity
This is a reaction in which fish is left out and the meat produces more histamine. It then can induce urticaria when eaten.